1. Field of the Invention
This present invention relates to a wireless communication system for communication handover by using different communication modes.
2. Description of the Related Art
Currently, different communication modes are used depending on communication distances when wireless communications are performed between a wireless communication device (initiator) to send data and another wireless communication device (target) to receive the data. Consequently, technologies for sending and receiving data by changing communication modes depending on communication distances are disclosed. In particular, a handover technology attracts attention, the handover technology by which authentication is performed by a communication mode of short-range wireless communication using near field communication (NFC) or the like in wireless communication, and thereafter the wireless communication is transferred (handed over) to and performed by another communication mode.
For example, Japanese Patent Application Laid-Open Publication No. 2007-74598 discloses a communication system in which communication between a video camera and a remote commander is performed by NFC in order that the video camera obtains available protocol information (media code representing Bluetooth®) and communication information (BT address) of a television (TV) receiver from the remote commander, and communication between the video camera and the TV receiver is performed by a communications protocol of the available protocol information based on the communication information.
Japanese Patent Application Laid-Open Publication No. 2007-97022 discloses a communication system in which a hard disk (HD) recorder obtains a communication function list of a TV from the TV via a repeater by a NFC mode, the HD recorder sends a request of contents data of the TV to the TV by a communication mode other than the NFC mode based on the communication function list, and after authentication of the HD recorder, the TV sends the contents data to the HD recorder by the communication mode which is the same as the communication mode by which the contents data is requested.
However, for example, when a personal computer (PC) and a digital camera can perform wireless communication by both NFC and a wireless local area network (LAN), and the digital camera tries to be connected with the PC by the wireless LAN, to which communication therebetween is handed over from NFC, in order to transfer image data, there is a case that the PC which is being connected to Internet by the wireless LAN is disconnected from Internet and connected with the digital camera.
In such a case, however, it is not defined whether a state of the PC returns to its state at which the communication between the PC and the digital camera is not handed over from the NFC communication to the wireless LAN communication yet and the PC is connected to Internet when the image transfer from the digital camera to the PC is completed, the digital camera moves out of an area during the image transfer, the area within which the digital camera and the PC are connected by the wireless LAN communication, or the wireless LAN communication therebetween is ended due to occurrence of a jamming beam or noise.
As a result, it is troublesome, after communication between wireless communication devices is handed over from one communication mode to another (handover is performed), to return a state of the wireless communication device, to which data is transferred by performing the handover, to its state before the handover is performed, and hence a problem arises that usability of such a wireless communication device is not good.